Study on the physiological and morphological effects of pitaya under drought stress

In order to explore the effects of different degree of drought stress on the pitaya plant morphological and physiological indexes，with Dahong pitaya plant as material，the morphological and physiological changes of pitaya plant were studied by using pot with water，the drought treatment after 40，47，54 days，respectively. The drought resistance characteristic of pitaya were also studied in this paper. The results showed that pitaya plant has a good drought tolerance，and it could adjust the physiological indexes in the body to adapt the drought conditions under defferent degree of drought stress，the change trend of different physiological indexes was different in drought period. With the deepening of drought stress，pitaya plant grew slowly，colour of stems deepened and surface of stems shriveled，the main root became short and number of root division changed less. Compared with controls，the content of free praline（ Pro） and soluble sugar remarkable up-regulated in treatment significantly，content of soluble protein and malondialdehyde（ MDA） was lower after first increases，peroxidase（ POD） activity significantly increased after significantly reduce，catalase（ CAT） activity also show the first trend lowered later，superoxide dismutase（ SOD） activity continued to decline.